Evaluation of hot mix asphalt resilient modulus based on aggregate morphological properties

Abstract

The standard material used to construct flexible pavement is aggregate. Hot mix asphalt consists of 85 to 95 percent by weight and 75 to 85 percent by volume mineral aggregate, and hot mix asphalt properties and performance are highly affected by these aggregates’ morphological properties. One of the most important variables determining the structural number, according to AASHTO design procedures, is the Resilient Modulus of these paving mixtures. In this research, coarse aggregate characteristics such as particle shape (cubical, blade, and disk), particle gradation (upper, middle, and lower specification limits), and surface texture (smooth and rough) were studied to explain their effects on the value of the resilient modulus. To achieve the goal of this study, Marshall Criteria were used to prepare the asphalt concrete mixture at the surface layer at its optimum asphalt content. Using a UTM25 device at a 40°C test temperature and a 200 ms load duration per ASTM D1234 designation, the resilient modulus was then tested. The findings indicate that aggregate morphological properties highly affect hot mix asphalt’s resilient modulus. Aggregate gradation had the most significant effect on the value of resilient modulus, followed by aggregate particles shape, and then, finally by surface texture.